Recently, restaurants are known to have a conveying apparatus including a circulation conveyance path which is laid along the eating and drinking tables or counters etc. in the eating and drinking guest area in the restaurant. In a kitchen, a cook makes a lot of vinegared rice balls and puts a various sort of ingredient or topping on them and shapes them into sushi pieces. Thereafter, those sushi pieces are placed on the plates and then transferred on the conveyance path of the conveying apparatus so that these dishes sequentially pass by the tables or counters in the restaurant. On the other hand, a guest chooses and picks up the dishes according to one's own taste from the conveyance path. In this way, the guests could have anything they like according to their own taste.
By the way, since those sushi pieces served on the plates are circulated along the conveyance path at a predetermined rate through the conveying apparatus as described above, the sushi pieces tend to become dried and may also be touched inadvertently by any of the guests during its circulation. Accordingly, there is a need for taking effective measures to keep the served sushi pieces clean and preventing them from drying during their circulation.
Conventionally, in order to solve the problems as described above, after having the respective dishes sealed with a plate cover formed separately, these dishes are carried out on the conveyance path. See Japanese Laid-Open Patent Publication No. 2001-299553.
However, by the conventional manner as described above, there is a need for a cook holding a plate cover on each dish or plate by hand while holding the plate cover with the other hand and transferring the dish with the plate cover one by one onto the conveyance path. On the other hand, it is required of a guest to remove the dishes according to one's taste from the conveyance path and then to take off the plate cover while holding it with one's hand. Resultantly, performing these actions is bothersome as a whole.
In addition, each time the plate cover is put on or removed from the respective dishes, since a cook and a guest holds the plate cover with one hand to put it on and remove it from each dishes, the plate cover might be soiled. Further, the plate covers removed from the dishes by guests are put on the relevant table or counter so that available space on the table or counter is reduced.    The prior art document: Laid Open (Unexamined) Japanese Patent Publication No. 2001-299553